What is the Difference in the Towbar Mainframe?:
In the beginning there was only one type of towbar in the UK. That was the two bolt on flange type towbar. This is the one that you still see the most of in the UK.
Becoming a part of the EC then brought a free market throughout the member countries which meant from the early 90’s we started seeing different type of towbars in the UK.
The purpose of this guide is to help explain the differences between the different towbars available in todays UK.
The Fixed Flange towbar:
The Flange towbar has been produced by UK towbar manufactures for over 50 years -
The Fixed Swan neck towbar:
The Swan Neck towbar has been manufactured for over 30 years, in close collaboration with all the major car manufacturers. It is important to note therefore that the car manufacturers' calibrations are all based on the "swan neck" design. This towbar is more usually seen in continental Europe, but due to its good looks popularity is now growing fast in the UK. The Latest news is that this type of towbar system is now being used by most al-
The Detachable towbar (Towball):
These towbars are designed for Individual motorists that have an eye for detail. The detachable towbar plays a major role here: the rear design of the vehicle remaining intact. When the ball is detached which is normally by a quick release lever system then there is nothing protruding from the rear of the vehicle.
CLICK HERE TO SEE A VERTICAL DETACHABLE DEMONSTRATION
Whats the difference in the Electrical Systems?:
A towbar is not just the metal work that fits under the vehicle but there is another part to the fitment, that part are the electric‘s.
There is a lot of confusion to what type of electric‘s there is available for a towbar fitment and what you exactly need in order to make the lights work on the back of your trailer or caravan and also keep the vehicle electric‘s safe.
This guide will cover this and hopefully throw some light on the subject.
Single Socket Electrics (12n)
This is the standard single electric point that you see on most towbar fitments. This is made up on one 7 pin electrical socket which is either mounted next to the towball or tucked under the bumper on some towbars. The purpose of this socket is to provide your road running lights for your attachment or lighting board.
This is basically all you need legally to tow but it is a little restricted in the functions it will provide. There is a myth that you can not tow a caravan with a single electric point but this is not true. It will however restrict your options with towing caravans and will prevent working some of your caravan functions.
Twin Electric Sockets (12s)
It will add the following functionality in your vehicle, reversing light, fridge working, caravan battery charger working, caravan interior light working.
This works off the 12 volt battery in the car and is meant to maintain the battery level and the fridge temperature. It will not cool the fridge down from it being hot for example.
The Switched feed for the caravan battery and the fridge is controlled by a number of ways.
Voltage Sensitive relay which will only trigger at 13.5 volts (When the vehicle is running) and feed the battery charger and fridge. When the engine is turned off the voltage will drop below 13.5 volts and this will cut the feed to these devices.
Twin electric‘s are ideal if you have long journeys or you like to camp in fields with no caravan services.
13 Pin Electric‘s
This is the continental style electrical connection. Both the 12n and the 12s electric‘s are contained within the socket which is about the same size as a UK trailer socket but contains 13 pins rather then 7 pins.
To connect instead of pushing in the plug you have to push in and turn to lock. This socket is used in mainland Europe and there has been a lot of talk of converting the UK to this method but no movement on this at the moment.
You can use this socket with UK 7 pin plugs which are on all UK trailers and caravans but you will need to use a convertor which will split the 13 pin electric‘s down to two 7 pin sockets or one single 7 pin socket depending on what you are towing.
This type of connection is ideal to use with a detachable towbar where there is only one space to mount one socket which sometimes can then be flipped out of view when not being used.
13 Pin Plug In Dedicated Electrics
These electric‘s have increased more over the last 16 months and can be obtained for the most popular towing vehicles. The main reason for the increase in popularity is due to the advancement of vehicles wiring as they are made to work in tune with the vehicles wiring structure integrating with any dashboard icons, stability programs and cutting out any reversing sensor feeds when connected so they do not sound when towing.
Each kit for each vehicle works differently and some are plug and play but some need you to take the vehicle to the main dealer in order to tell the vehicles computer that there is a trailer plug in wiring kit attached.
Towing Stability Program Explained (13 or 7 pin Dedicated Plug in Harness)
*Eliminates trailer yaw
Thanks to Dedicated 13 Pin Wiring Kits and years of in-
TSP is activated as soon as the trailer hitch connector is attached, and, in turn, the ESPPlus system then detects any yaw movement caused by the trailer – ESPPlus is normally a compulsory fit with TSP. This data is constantly processed and compared to the predetermined limits set in the system parameters. If a yawing movement begins and exceeds the preset limit, Just as a small example the car is slowed by throttle closure and brake application, until stability is restored. Should the yawing continue beyond three excessive movements, more intensive brake pressure is applied to steady the car and trailer.